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3481286ea0
This was not properly enforced and would be a spec violation on the peer's end. Also re-use a pong buffer to save on heap allocations if there are a lot of peers. The pong buffer is only read from, so this is concurrent safe.
72 lines
1.9 KiB
Go
72 lines
1.9 KiB
Go
package lnwire
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import (
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"bytes"
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"io"
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)
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// PingPayload is a set of opaque bytes used to pad out a ping message.
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type PingPayload []byte
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// Ping defines a message which is sent by peers periodically to determine if
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// the connection is still valid. Each ping message carries the number of bytes
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// to pad the pong response with, and also a number of bytes to be ignored at
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// the end of the ping message (which is padding).
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type Ping struct {
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// NumPongBytes is the number of bytes the pong response to this
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// message should carry.
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NumPongBytes uint16
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// PaddingBytes is a set of opaque bytes used to pad out this ping
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// message. Using this field in conjunction to the one above, it's
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// possible for node to generate fake cover traffic.
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PaddingBytes PingPayload
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}
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// NewPing returns a new Ping message.
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func NewPing(numBytes uint16) *Ping {
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return &Ping{
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NumPongBytes: numBytes,
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}
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}
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// A compile time check to ensure Ping implements the lnwire.Message interface.
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var _ Message = (*Ping)(nil)
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// Decode deserializes a serialized Ping message stored in the passed io.Reader
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// observing the specified protocol version.
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//
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// This is part of the lnwire.Message interface.
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func (p *Ping) Decode(r io.Reader, pver uint32) error {
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err := ReadElements(r, &p.NumPongBytes, &p.PaddingBytes)
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if err != nil {
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return err
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}
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if p.NumPongBytes > MaxPongBytes {
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return ErrMaxPongBytesExceeded
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}
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return nil
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}
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// Encode serializes the target Ping into the passed io.Writer observing the
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// protocol version specified.
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//
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// This is part of the lnwire.Message interface.
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func (p *Ping) Encode(w *bytes.Buffer, pver uint32) error {
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if err := WriteUint16(w, p.NumPongBytes); err != nil {
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return err
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}
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return WritePingPayload(w, p.PaddingBytes)
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}
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// MsgType returns the integer uniquely identifying this message type on the
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// wire.
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//
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// This is part of the lnwire.Message interface.
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func (p *Ping) MsgType() MessageType {
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return MsgPing
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}
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